Abstract 11019: Incidence and Predictors for Late Acquired Stent Malapposition of Drug-Eluting-Stents With Second-Generation Permanent and Biodegradable Polymer-Coatings - A Prospective, Randomized Comparison Using Optical Coherence Tomography

Introduction: The polymers releasing the drug of first-generation drug-eluting stents (DES) may induce allergic reactions and inflammation, resulting in late-acquired stent malapposition (LASM) with uncoverage of struts, and risk of stent thrombosis. The incidence and predictors of LASM in DES with different polymers designed to improve biocompatibility are unknown. Methods: Fifty patients with 59 lesions of interest were randomized to elective treatment with Everolimus-eluting stents (EES; n=17, 20 lesions)], Zotarolimus-eluting stents (ZES; n=15, 19 lesions), and Biolimus-eluting stents (BES; n=18, 20 lesions) and underwent optical coherence tomography after implantation and after one year. Results: After implantation 29 early stent malappositions (ESM) were documented in 29 lesions (49% of lesions), distributed to 11 lesions treated with EES (55%), 11 with ZES (58%), and 7 with BES (35%; n.s.). After one year 14 late stent malappositions (LSM) in 14 lesions (24%) were detected; nine ESM persisted (EPSM) after one year (1 EES, 6 ZES, 2 BES), whereas 20 ESM resolved. In addition, 9 LASM were documented (5 LASM in early well-apposed Stents, 4 LASM in Stents which also have EPSM). LASM was present in 7 hydrophilic polymer-coated ZESs (37%), in 2 fluoropolymer-coated EESs (10%), and in none of the biodegradable polymer-coated BESs (p=0.003). Independent predictors of LASM were the vessel treated (RCA as vessel with high motion; p<0.022) and type of polymer (biodegradable or permanent; p<0.035). Conclusion: The incidence of ESM and EPSM were similar, whereas the incidence of LASM was different in second-generation DES with different polymers. Biodegradable polymer prevented LASM, stent locations with significant vessel movement (RCA) enhanced LASM.